This invention relates generally to removable input/output (I/O) devices of the type used with host systems such as desktop and portable personal computers, peripherals, and the like, for directly connecting the host system to an information transfer system using standard modular communications plugs.
As is well known, many of today""s laptop, notebook, desktop and other computers, as well as computer peripherals and other electronic products, are designed to receive removable devices such as cards conforming to standards established by the Personal Computer Memory Card International Association (PCMCIA). These standards define the electrical and physical specifications of the card including the interfaces between the card and the port or slot into which the card is inserted. The specifications include a 16-bit PC Card interface and a 32-bit CardBus interface. The PCMCIA standards also specify three card form factors, called Type I, Type II and Type III. All three card types measure the same length (85.6 mm) and the same width (54.0 mm), and differ only in overall thickness. Thus, the Type I card has a thickness of 3.3 mm; the Type II card, 5.0 mm; and the Type III card, 10.5 mm. PCMCIA cards may be used for various purposes. For example, Type I cards are typically used for memory devices; Type II cards are typically used for I/O devices, as will be described below; and Type III cards are typically used to house rotating mass storage devices (disk drives). Presently, Type II cards are used principally as communication links, for example, for connecting the user of a host system such as a portable computer to an Ethernet LAN, as a data/fax modem for connecting the user to a subscriber telephone line system, or as a combined LAN and modem card. In one popular arrangement, an adapter cable is used to couple the relatively thin Type II card to the much larger, standard RJ-11 or RJ-45 receptacle of a telephone line or Ethernet network. A drawback of this arrangement is that one or more bulky adapter cables must be carried (in addition to the computer) by the computer user in order to connect the computer to a LAN or telephone line system thereby defeating at least to some extent the advantages afforded by portable computers; also, these adapter cables are often lost. Another disadvantage of adapter cables is that the connection between the thin card and the cable is inherently fragile mechanically and subject to losses of electrical contact with a consequent loss of data transfer.
One solution to the problem of incompatibility between the PCMCIA Type II standard communications card and the RJ-type connector is to add to the rear end of the Type II card an enlarged housing enclosing a receptacle sized and configured to receive an RJ-type connector plug. The incorporation of such an RJ receptacle housing allows the 5 mm Type II communications card to interface directly with a LAN or telephone system using an existing LAN or telephone cable with an RJ-11 or RJ-45 modular plug at each end. However, although this approach eliminates the need for a separate adapter cable assembly, the housing on the end of the card for receiving the RJ-type connector projects from the host system enclosure often requiring the removal of the card when transporting a portable computer in an attache case or the like.
Another approach to the elimination of the need for external adapter cables is a communications card that allows an RJ-type modular plug to be inserted directly into an aperture formed in a retractable access portion of a Type II communications card. Such an approach is disclosed, for example, in U.S. Pat. No. 5,183,404 issued Feb. 2, 1993. Yet another approach to eliminating the need for adapter cables is disclosed in International Application No. PCT/US94/13106, published May 18, 1995 under the Patent Cooperation Treaty (PCT) as Publication No. WO 95/13633 (corresponding to U.S. Pat. No. 5,773,332). FIG. 21 of this PCT publication shows a Type III card incorporating in the rear thereof a pair of RJ-xx series receptacles (specifically RJ-11 and RJ-45) for directly connecting the card to a LAN network and/or telephone line.
An overall object of the present invention is to provide an improvement of the device disclosed in the aforementioned PCT publication.
In accordance with one specific, exemplary embodiment of the invention, there is provided a device adapted to be received by a port in a host system for connecting the host system to a digital information transfer system. The device comprises a housing having longitudinal sides, a transverse front end and a rear portion, at least the rear portion of the housing conforming substantially to the PCMCIA Type III thickness standard. A substrate enclosed within the housing carries circuit elements and a connector at the front end of the housing is connected to circuit elements on the substrate. The connector is adapted to be received by a corresponding connector within the slot of the host system. The rear portion of the housing defines at least one forwardly extending receptacle, the at least one receptacle including contact wires coupled to circuit elements on the substrate. The at least one receptacle is sized and configured to receive a standard RJ-type modular plug, the modular plug including contacts adapted to engage the contact wires in the at least one receptacle when the plug is inserted in the receptacle so that the device is adapted to be directly connectable to the digital information transfer system utilizing the standard RJ-type plug. The substrate includes a rear margin carrying a contact block having a plurality of contact wires. Each contact wire has a first terminal portion, or solder tail, connected to circuit elements on the substrate, and a second terminal portion extending into the at least one receptacle, the second terminal portion of the contact wire being shaped and positioned for engagement with a corresponding contact on the RJ-type modular plug.
In accordance with another aspect of the invention, the contact block comprises a base and a transversely extending, vertical wall mounted on the base. The wall has a front face, a rear face and a bottom face, and further includes at least one contact section adapted to make electrical connection with said at least one modular plug. The at least one contact section of the wall includes surfaces for retaining the contact wires against lateral displacement and further includes a recess in the bottom face. A plurality of shaped contact wires are carried by the contact block, each contact wire including portions engaging the contact wire retaining surfaces, each contact wire further including a first terminal portion or solder tail extending into the recess for connection to the substrate and a second terminal portion extending from the rear face of the wall, the second terminal portion being adapted to be engaged by a corresponding contact on the modular plug.
In accordance with yet another aspect of the invention, the first terminal portion or solder tail of each contact wire extends rearwardly within the associated recess and a portion of the rear face of the vertical wall of the contact block is shaped to facilitate access to the solder tail of each contact wire. Preferably, the shaped portion of the rear face of the vertical wall comprises a beveled surface.
The contact block is designed to minimize its encroachment on the adjacent substrate. Thus, the rearwardly extending solder tail of each contact wire is connected to the traces on the rear margin of the substrate as close as practicable to the rear edge thereof. After fabrication of the subassembly comprising the substrate and contact block, the recesses and beveled surfaces defined by the contact block wall facilitate inspection of the integrity of the solder joints connecting the contact wire solder tails to the substrate and provide sufficient space to permit resoldering if necessary.
In accordance with another aspect of the present invention, there is provided an improved enclosure for an I/O device adapted to be received by a port in a host system. The improved enclosure comprises a housing including a top wall and longitudinal, parallel side walls depending from the top wall, the longitudinal side walls and top wall defining an internal cavity for receiving a substrate carrying electronic components. The housing further has a forward end, a rear portion and a rear end surface, the rear portion defining at least one receptacle extending forwardly from the rear end surface and sized and configured to closely receive a standard RJ-type modular plug. At least the rear portion of the housing conforms substantially to the PCMCIA Type III thickness standard. A bottom cover panel encloses the cavity, the bottom cover panel including parallel, upwardly extending side flanges configured to nest within the side walls of the housing. In accordance with another feature of the improved I/O device enclosure, the side walls of the housing and the upwardly extending side flanges of the bottom cover panel are adapted to receive and retain longitudinal side margins of the substrate. The housing and bottom cover panel thereby define an enclosure maximizing the usable substrate surface area. Still further, the housing may comprise a one-piece, unitary molded plastic structure. Alternatively, to facilitate fabrication of the enclosure, the rear portion of the housing may constitute a receptacle body defining the at least one receptacle, the receptacle body and the remainder of the housing comprising separate, molded plastic structures bonded by sonic welding, for example, along mating joinder surfaces.